comparing two samples

Hi all I hope all is great with everyone. I'm new on here so sorry to get straight down to my query and hope that someone might be able to point me in the right direction. Thank you. So: I have a prospects direct mail file and I'm testing a new message, (One change). To ensure it’s the...

Dear All, I would like to test hypotheses like the following example: Effect A is weaker than effect B. For Effects A and B, I have a 2 (error: present vs. absent) x 2 (group: control vs. experimental) contingency table, thus getting chi and e.g. a phi-coefficient. My question is: How...

Hi, I am looking to compare day and night time depths for basking sharks in SPSS. I found that if I have day depths for all sharks together I can use a Mann Whitney U test as then the data is independent (they are non normally distributed). However, I also need to compare each shark...

I have a quick query about measures of sample accuracy in a tracking study with an overlapping (common) sample, and couldn't see anything here already. Perhaps it's a new one! I have a large tracking study with a sample size of n=3,600 . The confidence interval for each track is therefore...